go 获取指定网卡的ip

package main

import (
	"errors"
	"fmt"
	"net"
)

func main() {

	ip, err := GetInterfaceIpv4Addr("eth0")
	if err != nil {
		fmt.Println(err)
	}
	fmt.Println(ip)

}

func GetInterfaceIpv4Addr(interfaceName string) (addr string, err error) {
	var (
		ief      *net.Interface
		addrs    []net.Addr
		ipv4Addr net.IP
	)
	if ief, err = net.InterfaceByName(interfaceName); err != nil { // get interface
		return
	}
	if addrs, err = ief.Addrs(); err != nil { // get addresses
		return
	}
	for _, addr := range addrs { // get ipv4 address
		if ipv4Addr = addr.(*net.IPNet).IP.To4(); ipv4Addr != nil {
			break
		}
	}
	if ipv4Addr == nil {
		return "", errors.New(fmt.Sprintf("interface %s don't have an ipv4 address\n", interfaceName))
	}
	return ipv4Addr.String(), nil
}